What is Authoritative and Non-authoritative DNS Server? Understand the difference between Authoritative and Non-answer for DNS query in simple words.
What is Non-Authoritative DNS Server?
Non-authoritative name servers do not contain original source files of domain’s zone. They have a cache file for the domains that is constructed from all the DNS lookups done previously. If a DNS server responded for a DNS query which doesn’t have original file is known as a Non-authoritative answer.
For example, we query for DNS records of domain linuxmasterswiki.com and Google’s open DNS server 184.108.40.206 responded for this query which doesn’t contain domain’s original zone files. This answer is known as a Non-authoritative answer.
$ nslookup linuxmasterswiki.com Server: 220.127.116.11 Address: 18.104.22.168#53 Non-authoritative answer: Name: linuxmasterswiki.com Address: 22.214.171.124 Name: linuxmasterswiki.com Address: 126.96.36.199
What is Authoritative DNS Server?
An authoritative name server is a name server that has the original source files of a domain zone files. The is where domain administrator has configured the DNS records for a domain. Authoritative DNS server can be master DNS server or its slaves.
For example – domain linuxmasterswiki.com’s authoritative are alec.ns.cloudflare.com and athena.ns.cloudflare.com. If you directly query to these DNS servers, they will return authoritative answer because they have the original files of domain zone.
$ nslookup linuxmasterswiki.com alec.ns.cloudflare.com Server: alec.ns.cloudflare.com Address: 188.8.131.52#53 Name: linuxmasterswiki.com Address: 184.108.40.206 Name: linuxmasterswiki.com Address: 220.127.116.11